Impact of different visualization devices on accuracy, efficiency, and dexterity in neurosurgery: a laboratory...

Extracorporeal telescopes (exoscopes) have been the latest addition to the neurosurgeons' armamentarium, acting as a bridge between operating microscopes and endoscopes. However, to the authors' knowledge there are no published preclinical laboratory studies of the accuracy, efficiency, and dexterity of neurosurgical training for the use of 2D or 3D exoscopes compared with microscopes.

In a controlled experimental setup, 22 participating neurosurgery residents performed simple (2D) and complex (3D) motor tasks with three visualization tools in alternating sequence: a 2D exoscope, 3D exoscope, and microscope, using a block randomization model based on the neurosurgeons' prior training experience (novice, intermediate, and senior: n = 6, 12, and 4, respectively). Performance scores (PS; including error and efficiency scores) and dexterity scores (DS) were calculated to objectify the accuracy, efficiency, and finesse of task performance. Repeated measures ANOVA analysis was used to compare the PS, DS, and cumulative scores (CS) of candidates using the three visualization aids. Bland-Altman plots and intraclass correlation coefficients were generated to quantify intraobserver and interobserver agreement for DS. Subgroup analysis was performed to assess the impact of participants' prior training. A postexercise survey was conducted to assess the comfort level (on a 10-point analog scale) of the participants while using each visualization tool for performing the suturing task.

PS, DS, and CS were significantly impacted by the visualization tool utilized for 2D motor tasks (p < 0.001 for each), with the microscope faring better than the 2D exoscope (p = 0.04) or 3D exoscope (p = 0.008). The PS for the 3D object transfer task was significantly influenced by the visualization aid used (p = 0.007), with the microscope and 3D exoscope faring better than the 2D exoscope (p = 0.04 for both). The visualization instrument used significantly affected the DS and CS for the suturing task (p < 0.001 for both), with the microscope again scoring better than the 2D exoscope (p < 0.001) or 3D exoscope (p = 0.005). The impact of the visualization aid was more apparent in participants with a shorter duration of residency (novice, p = 0.03; intermediate, p = 0.0004). Participants also felt the greatest operational comfort while working with a microscope, 3D exoscope, and 2D exoscope, in that order (p < 0.0001).

Compared with 3D and 2D exoscopes, an operating microscope provides better dexterity and performance and a greater operational comfort level for neurosurgeons while they are performing 2D or 3D motor tasks. For performing complex 3D motor tasks, 3D exoscopes offer selective advantages in dexterity, performance, and operational comfort level over 2D exoscopes. The relative impact of visualization aids on surgical proficiency gradually weakens as the participants' residency duration increases.